This invention relates to fluoropolymers and more particularly to curable polyfluoro prepolymers.
Fluoropolymers are used as binders in high-density explosives and propellants and in energetic compositions requiring a high degree of thermal stability. For example, fluoropolymers are used extensively in such compositions which are pressed. However, very few fluoropolymers exist which have functional groups such as hydroxy which are suitable for curing and thus can be used as binders in castable or extrudable compositions. Two known examples of such polymers are the fluoropolyethers FC2202 and L9019 made by the 3M Company. While useful for some purposes, these polymers are expensive and completely fluorinated. The absence of hydrogen limits the compatibility of these polymers with conventional plasticizers, curing agents, and other polymers.